The accurate identification of individuals prone to the development of schizophrenia is necessary for the study of environmental and biological factors that heighten or reduce the probability of developing this disorder. The detection of such vulnerable individuals would also help in prevention efforts. Unfortunately, prior research on the psychometric detection of schizophrenia-proneness has been limited in that what has been detected is more generally psychosis-proneness. Also, there are concerns that prior research is limited by the study of non-minority college students that are not representative of the general population. In this revised application it is proposed that social anhedonia may be a promising indicator of the latent liability for schizophrenia. The role of social anhedonia in the development of schizophrenia will be studied in a randomly ascertained community sample of 18 year-olds who will be selected independently of race, education, or socio-economic status. First, this study will examine the hypothesis that taxometrically identified socially anhedonic individuals are at risk for schizophrenia and schizophrenia-spectrum disorders. Subjects (social anhedonics and controls) will be assessed for schizophrenia and other Axis I disorders, schizophrenia-spectrum personality disorders, and psychotic-like experiences at a base assessment and again at a 3-year follow-up. Second, to understand the range of outcomes in at-risk individuals, other individual difference variables will be assessed that may potentiate the expression of schizophrenia and schizophrenia-spectrum disorders. It is hypothesized that, in vulnerable individuals, reduced social support, elevated trait negative affect, and attentional impairment at the base assessment will increase the probability of clinically diagnosable illnesses and generally poorer functioning at the follow-up assessment. Third, the proposed investigation will examine the hypothesized genetic risk for schizophrenia associated with social anhedonia by directly assessing schizophrenia-related diagnoses and characteristics in the biological parents of social anhedonics and controls.